What Causes the Abnormal Noise When Starting an Automatic Transmission Car?
2 Answers
Automatic transmission cars may produce abnormal noises when starting due to the following reasons: 1. Engine noise: Abnormal noise from the engine indicates that there may be multiple issues in the engine compartment. Most people can identify the noise as coming from the engine compartment based on the sound source. The noise is usually a sharp metallic sound or a whistling noise. When the engine produces abnormal noises, it should be repaired promptly to prevent further damage. 2. Transmission noise: Abnormal noise from the transmission manifests as a "rustling" sound inside the transmission while driving, which disappears when the clutch or accelerator is pressed. There may also be a whistling-like sound during gear shifts. If a specific gear produces noise, it is definitely related to the components affecting that gear's transmission. If all gears produce noise, it is often due to a fault in the constant-mesh gear shaft or insufficient transmission oil.
I've worked in the auto shop for many years and seen plenty of automatic transmission vehicles making strange noises during acceleration. There could be several reasons: The torque converter might be faulty - this component at the front of the transmission is responsible for power transfer during acceleration, and if worn or low on fluid, it can produce squeaking or creaking sounds. Then there's the transmission internals - damaged gears or oil pumps often cause humming noises during low-gear acceleration, especially common in older vehicles. Another possibility is loose drive axles (the parts connecting to the wheels), which become more noticeable when turning while accelerating. The braking system can contribute too - if brakes aren't fully released, they'll create grinding sounds when wheels rotate. And if engine mounts or suspension ball joints are worn, vehicle movement causes noticeable rattling. These noises range from minor to serious - small issues are quick and inexpensive to fix, but ignoring them could lead to major problems like engine damage or compromised handling. Pay attention to noise sources during acceleration and get professional diagnostic scans promptly to avoid driving anxiety.
